1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine, a complex machine including a copying machine, facsimile, and printer, etc.
2. Background of the Invention
Image forming apparatuses include copying machines for copying original images, and multifunction peripherals (MFPs) each having functions of a copying machine, a facsimile, a printer, etc. Sometimes, these copying machines and MFPs are used to print images on special paper such as thick paper, instead of ordinary paper. When thick paper is printed on as special paper, the settings of the copying machines and the MFPs should be changed to the xe2x80x9cthick paper print setting.xe2x80x9d In the thick paper print setting, the process conditions such as the transfer condition, the charging condition, the fixing condition, etc. are changed from those for ordinary paper to those for thick paper. Conventionally, such thick paper print settings have been adjusted by users.
However, there is a case where a user determines wrongly whether the paper to be printed on is ordinary paper or thick paper, resulting in that he/she does not implement the thick paper print setting when thick paper is used for the printing. In this case, many problems may arise due to the differences between the process conditions for thick paper and the process conditions for ordinary paper. For example, sometimes an image printed on thick paper is thinner than the original image to be copied; sometimes, there is a white portion, to which toner is not adhered, in an image printed on thick paper; and sometimes the appearance of a printed image is inferior to and dirtier than that of the original image.
The present invention is proposed in view of the above-described problems, and the object of the present invention is to automatically discriminate the thickness of a sheet of paper being conveyed, and to carry out a process control suitable for the thickness of the sheet of paper.
An image forming apparatus according to the present invention includes: a discrimination circuit for detecting a conveying load at a time a sheet, on which an image is to be formed, is conveyed through a curved conveying path, for discriminating a thickness of the sheet based on a detected value of the conveying load, and for generating a process control signal in order to carry out a process control suitable for the thickness of the sheet based on the discriminated thickness; and a process control circuit for carrying out the process control suitable for the thickness of the sheet in response to the process control signal received.